Operations carried out
Lens Nikkor & Nikon
Nikkor H-C 5cm f/2 with 39 screws
A lens given to me by a collector friend.
It had a dent on the front of the filter holder and a few micro-scratches on the front.
This lens also had a back focus of +/- 10 cm for a point at 1 metre.
This isn’t really a problem with conventional shots if you close the aperture properly, but it does degrade images at wide apertures.
This shock doesn’t make dismantling easy, as there isn’t enough depth to use the reverse clamp.
I therefore made two notches to gradually unscrew the front unit and straighten the twisted part.
The first check showed that the rangefinder was focusing just right, but the problem lay elsewhere.
Its assembly is unusual, as some threaded rings are blocked by long, tiny screws. In fact, when I dismantled it, I noticed that there were two screw marks, which implies that this lens had already been dismantled.
Once the principle of assembly is understood, even delicate dismantling can be carried out without too much difficulty. Removing the front block reveals the focusing ring, which has a small detent ball held in place by a flat spring screwed to the barrel, marking the end of the coupling with the rangefinder (clever, isn’t it?).
Next, dismantling the rear mount reveals the single linear guide fixed to the barrel, and the double helical ramp.
Further disassembly (still using micropoint screws) enables the ramps to be removed. Of course, markers are essential.
The ramps were cleaned and re-greased (not too much with Helimax XP) and then temporarily reassembled so that I could check my set-up by replacing the front unit.
Nikon had provided two types of additional adjustments to the correct positions of the two ramps.
1/ The position of the boom block.
2/ The position of the focus ring.
Adjustment takes a long time, because it’s a matter of 1/10 of a millimetre, or even less…
As the full aperture isn’t really very well defined (it’s an old lens with a long history), I had to do a lot of checking to find the right calibration.
The micro-scratches on the front were reduced as much as possible by gentle polishing with Polywatsh.
In the end, reassembled, this lens has the ‘vintage’ look you would expect from a 1946 lens.
The images from a quick test were taken with a digital Leica M, using a K&F adapter ring for the 50mm focal length.
All we can see is the typical rendering and some weaknesses in high light.
Colours are accurate but very saturated. Black and white suits it perfectly because it exploits the charm of this lens.
A little history: https://imaging.nikon.com/imaging/information/story/0034/
Nikon 85mm f/1.8 AF
This 85mm is one of the best in the range.
Following a shock, the diaphragm was loose and the focus was too firm.
Complete dismantling, adjustment of the focusing ramp, re-installation of the blades.
Nikon 17-35 f/2.8 AFs
A remarkable quality lens that replaced the 20-35 AFd.
This one had a broken diaphragm drive.
A large number of parts, an imposing electronic circuit and the SWF motor made the operation tricky.
It was necessary to dismantle all the internal components to replace the faulty part.
Now repaired, it’s working perfectly again.
Nikon 14 - 24 f/2.8 AFs
Remarkable quality optics.
This one had the zomming ring stuck at the 14mm position following a shock.
A large number of rings, the electronic circuit and the SWF motor made it a tricky job.
It was necessary to dismantle all the internal components to get to the sticking point.
Now repaired, it’s working perfectly again.
Nikon 20mm f/2.8 AFd
This 20mm f/2.8 AFd had a haze problem that resulted in hazy images at all apertures.
The lens group responsible for the problem was dismantled, oven stripped, cleaned and re-bonded with optical UV glue.
After this treatment, this 20mm lens regained its brilliance and sharpness.
Nikkor 55mm f/1.2
This 55mm f/1.2 pre AI was in used condition, with the focus ring blocked and lots of fungus on the lenses.
It was completely dismantled, the helicoils cleaned and regreased, the diaphragm drive repaired and the lenses treated.
After all this care, it was reassembled and is once again functional.
In use, this lens should be considered in the light of its performance at the time.
Nikon 20mm f/2.8 AI
This 20mm f/2.8 AI had a haze problem that resulted in hazy images at all apertures.
The lens group responsible for the problem was dismantled, oven stripped, cleaned and re-bonded with optical UV glue.
After this treatment, this 20mm lens regained its brilliance and sharpness.
500mm f/8 - Catadioptrique
This 500mm f/8 with mirrors had several problems.
A shock had slightly bent the bayonet, the focus was very firm and there was a lot of mushrooming.
Disassembly is not complicated, reassembly much more so.
A few pointed screws hold the various bushes together, allowing the barrel and front end to be separated.
The bayonet was straightened with an inverted vice. The helicoils were cleaned and regreased.
The front lens was treated for fungus, as was the inside of the barrel, and the mirrors were cleaned.
Reassembly was more difficult. Putting the various rings back in place was easy, thanks to a few markings and photos.
On the other hand, reassembling the helicoidal was difficult, as the millings have a very specific position…
Mirror optics, built on the same principle as telescopes, don’t have a very good reputation.
Poor image quality, difficult to focus, low luminosity, ‘doughnut’ background effect on bright spots
not always appreciated. It’s true that, in a series of images, too many mirror lens effects can be tiring.
And yet… By deliberately shifting the focus, you can create pictorial effects that I personally appreciate.
Micro Nikon 60mm f/2.8 AF
This 60mm is the AF model of the famous previous 55mm manual focus versions. A banal focusing problem.
Banal, because unlike the manual models, focusing is not done by greased helical ramps, but by a system of slides.
On rare occasions, one of these slides may become slightly unscrewed, blocking or slowing down the mechanism.
Complete dismantling, check of the focusing slides, dismantling and re-installation of the slides with threadlocker, test at f/2.8.
Nikon 50mm f/1.4 pré AI
This 50mm f/1.4 is a great classic of its kind. It has undergone aesthetic, mechanical and optical evolutions over the course of its production.
A little worn, but pre-AI all-metal versions often are, its problem was its overly firm focus.
It’s not unusual for lubricants to lose their qualities with time and use.
Complete dismantling of the helices, cleaning and greasing. Checked diaphragm and lens condition, reassembled.
Nikkor 135mm f/2.8
description
I received as a gift from a very recent friend in the USA, this 135mm Nikkor in parts.
Its owner couldn’t put it back together.
The screws were very carefully classified in small boxes, according to the order of dismantling.
I did a partial reassembly to test the focus which was slightly shifted backwards.
A very classic error is to remove the linear guide from the helical rings, without taking position marks.
The rear ring after its reassembly was offset by one notch, which is tiny, but no longer allows focusing on infinity.
This optic also includes an adjustment by the part which locks the focusing ring in the infinity and minimum distance position.
To avoid dismantling the helical ring and spending a long time finding the right position, I tried adjusting it with the point locking piece.
The difference in position was less than 2 millimeters. The control gave perfect focus to infinity and the shortest distance.
Obviously, Nikon had planned this adjustment possibility, because in other lenses from the same brand, the locking part is fixed.
There are a few important details to know for this optic.
1/ It is essential to remove the rear lens and its protection to correctly replace the diaphragm selection drive.
2/ The depth of field indicator ring must be glued to the chrome ring to have correct positioning.
3/ The front group is dismantled in three stages.
a/ remove the needle screw through a hole in the sun visor.
b/ unscrew the filter holder ring at the front, with a rubber plug of the correct diameter.
c/ unscrew the front optical unit, using a spanner.
The winding is a classic Nikkor, each part has a logical place, as simply as it is possible to make an optic.
Micro Nikkor 105mm f/2.8
description
text
Micro Nikkor 55mm f/2.8
There are two common problems with 55mm micro lenses.
1/ The focusing ring is too firm. 2/ An oily diaphragm.
In both cases, the optical unit must be removed from the main barrel. This starts by removing the rear bayonet. (Be careful, the screws are sealed with varnish, use nail varnish remover).
The optical unit is held in place by 3 internal screws.
For the focusing ring, it is, in most cases, the fine helical ramps of the CRC (short focus correction) that are at fault, it is located at the front of the unit.
Disassembly is not difficult, but requires a great deal of care. If it is not reassembled correctly, the optical quality will deteriorate. To do this, positioned on infinity, you need to mark precise positions. Of course, you also need to mark the ramp separations.
The diaphragm block must be dismantled and degreased if it is oily.
The CRC ramps must be degreased, cleaned and lubricated very sparingly with fine grease.
Reassembly is the reverse of disassembly.
Nikkor 35mm f/2.8 early model
Why ‘early’?
When the Nikon F came out, a range of lenses was created at the same time. They are called ‘TickMarks’.
These lenses are rare and sought after by collectors.
Subsequently, another range of lenses was created that are mechanically very similar to the TickMark, but the numbering differs.
Disassembly is very different from the pre-IA Nikkor lenses, in particular the aperture ring, which is screwed on instead of clicked on.
Nippon Kogaku Nikkor C 35mm f/3.5
This Nikkor S 35mm f/3.5 was in very poor condition. It had either drowned or spent a long time in a damp environment.
The diaphragm was rusty, the lenses had turned ochre and the focus was blocked.
The lens barrel was dismantled, and the metal of the diaphragm was treated so that it did not regain its original appearance.
Treatment of the lenses, treatment of the rust in the barrel. Lubrication of the helicoils.
Reassembly.
In the end, although imperfect, this little Nikkor was usable again.
Nikkor 35mm f/2.5 Nikonos
This Nikkor 35mm f/2.5 Nikonos was in poor condition. Although it was designed to be used in humid environments
it showed signs of fungal attack and general blockage.
No doubt some faulty seals were the cause of this deterioration.
The upper protection for the cocking lever was missing. It was replaced by a little home-made DIY.
A simple plastic chair leg with the right diameter, cut to size and glued in place, provides the same protection as the original.
It’s relatively easy to dismantle, but it’s worth noting that the compactness of the design and the controls mean that there are a number of things that are different from the original,
there are a number of different elements compared to the classic Nikkors.
Some parts have been cleaned and degreased in an isopropyl alcohol bath.
Mushrooms need to be treated on both the lenses and the metal parts.
Dismantling and greasing the helical ramps.
Reassembly is the reverse of disassembly.
Nikon 24 - 50 f/3.3-4.5 AF
This Nikon 24 – 50 f/3.3-4.5 AF zoom lens had a mushrooming problem on several lenses.
It is easy to dismantle in order to intervene. Care must be taken, as this lens is made of polycarbonate on the outside with special screws.
The internal parts are classic Nikon, glass and metal.
Mushroom treatment: isopropyl alcohol and 50/50 hydrogen peroxide.
After this treatment, this zoom regained its brilliance and sharpness.
Nikon Micro 105mm f/2.8 AFs G
Rescue…
This is a high-quality lens, both technically and optically.
Robustly built, but like all photographic equipment, it can’t take a nasty shock.
Externally, it appeared to be in good condition, but it was rendered completely unusable by a
side at the front.
As a result, nothing worked any more, manual and auto focus were totally blocked, in short a lens that was fit to become a paperweight.
These lenses are a judicious mix of relatively classic mechanics (such as zoom)
and 100% electronic management with the famous ultrasonic SWF motor, plus a stabiliser.
Dismantling is extremely rigorous, time-consuming and even dangerous, as there are many layers and wires welded together. You have to do it with at least an antistatic wrist strap.
I spent roughly two full days dismantling it, finding and solving the ‘problems’, partially reassembling it for tests, etc etc. The focus ring had a nice hole in it.
The focusing ring had a nice, marked bump, a slight haze and the front ring was even a little cracked.
The front can be removed by lifting a plastic cover glued around the front.
This reveals a large number of black screws. The headlamp can then be removed.
Underneath, another set of chrome screws is used to remove the front ring.
At this point, the focus ring can be removed.
The shock could not be straightened, due to lack of space and, above all, because it was very localised.
So I opted for internal grinding to reduce the thickness of the metal and restore a more logical shape.
But that was only the first problem…
The barrel, some of the electronics and the connectors are removed from the rear.
Disassembly of the mount, the rear protection, the casing contactor and the rear barrel using 4 long screws on the outside,
(one of which is already a bit battered).
To gain full access to the inside of the optics, unscrew 3 Teflon slides on the side of the motor,
dismantle the mode selector block, not forgetting to remove the cable previously disconnected from the electronics block,
3 screws, including a large one hidden under the VR logo.
You can then remove the central part of the barrel.
Next, disconnect the cables, unsolder the wires, remove the SWF motor (the soldering must be completely flat, otherwise the motor will not come out),
otherwise the motor won’t come out), dismantle the distance display, brushes (one of which had been badly damaged), etc etc.
We found that the rotating ring that drives the motor was jammed, and in any case, manual rotation required too much force for an AFs lens.
It is held in place by two large screws, which attach two tiny ball bearings.
Removing them wasn’t easy, and for good reason… The inner workings were flawed. One of the bearing rotation slots had become too narrow and the other wider than normal. Loss for loss,
I straightened the inner barrel little by little (I’m keeping the method confidential, you’d call me mad!!).
Finally, the bearings worked again, and on reassembly, the motor drive ring
has regained its flexibility and drives the focusing mechanism normally.
Reassembly is of course the opposite of disassembly, the soldering of the wires to the sheets is very delicate,
No soldering iron too hot and of course a little flux.
The motor works and focuses, although it has a slight tendency to slip.
A problem that couldn’t be solved without Nikon’s SWF control electronics.
The focus ring is a little firm, but usable. One lens saved, even if it’s not totally perfect…
It would have been ideal to replace a few parts with new ones, but well…?
This really isn’t the type of lens I prefer, long live good, classic mechanics.
Nikon 70-210 f/4 série E
I have a particular affection for the E series.
No doubt because they are unloved, neglected, too amateurish, not professional enough, not robust, not good, etc etc etc.
What a mistake, there are recognised gems that are well worth the AI/AIs, just to mention the 100mm.
Found for cheap in Japan, this optic in perfect aesthetic condition had a few mushrooms.
Disassembly is relatively simple, but there are a few points to bear in mind.
For the rear lens, disassembly of the classic mount, without forcing the 5 screws.
Removal of the diaphragm ring… Watch out for the little ball in the detent.
Removal of the 3-screw chrome ring.
Removing the tube with the PdC engravings 3 screws.
Slide it forward.
Dismantling the rear block, 4 large-head screws.
Look out for the long diaphragm rod. Watch out for the mechanical draft elements.
This block is removed towards the rear, freeing the rear lens group.
To unscrew, use a little nail varnish remover, it’s stuck. There are still some nice curved lenses.
Disassembly and treatment of the mushrooms, then reassembly.
The front group is held in place by a small needle screw; always use a little solvent before unscrewing it.
The front group can be unscrewed in the usual way, but the grip is delicate, so I used a rubberised garden glove.
Mushroom treatment and reassembly.
Now it’s ready to go!
Micro Nikkor 200mm f/4 AF
Nikon Much more than a legend
I decline all responsibility if you damage your toys !!! There are also professionals to do this work 😉